I wasn’t sure which section to post this in, but my question is more about the rail than the weapon and I figured I’d get more response here.

I have a Daniel Defense MK 18 upper with a SB tactical pistol brace. I really like it, and have had no issues. The only thing that irks me is the quad rail. I have been thinking about changing mine out for a quality mloc rail. I’m thinking that it would shave some weight, be more ergonomic, and look better. What does the forum think? Should I swap it, or should I just buy a different quality upper (BCM 11”) and sell the DD?

10mm lays waste to entire cities, cuts through diamonds and will tear Superman a new asshole. - Parabellum

Sex offenders can not be rehabilitated. It's in their wiring. They should not be released back into the general public. On the other hand they should not be warehoused either. I think they should be executed.....Spectre

When someone tries to kill you, it doesn't matter how they are doing it. You're in mortal danger, and it's time to try to kill them back.

Arc.___

Kill every last one of these goddamned animals. We need a president with balls. We need leadership. We should be carpet bombing these barbarians wherever we find them, and we should be looking for them 24/7. We have to unleash Hell upon them. They understand nothing but death, so death is what we should bring them, wholesale.... Para

I left "practical" behind many years ago. It was covered with my first Glock 19. (Fredward)

You should run the numbers first:- cost of buying a new BCM upper- cost of buying a new Mlok rail- expected sales value of the existing DD upper- cost of Mlok accessories, especially if existing rail accessories will be replaced

My situation is a little different, but I am gradually transitioning my ARs from quad rail to Mlok. I began with a new Mlok rail when I recently replaced a shot-out barrel. I definitely prefer the new Mlok over the old quad rail. I will replace the quad rails on other uppers over the next couple of years as I shoot out their barrels.

A MK 18 upper is an actual desirable 'thing'. No chance I'd modify it to change the rail. Now normally I detest quad rails but my M18 with covers doesn't bother me at all. the whole thing is short so the weight savings will be nominal for any change and what it looks like seems to me to be an odd criteria. I hate the look of MLOC.Net, probably best would be just get another upper and sell what you have. I wouldn't head that direction given that almost anything you replace it with will be a lesser product.

“So in war, the way is to avoid what is strong, and strike at what is weak.”

Top SBR is a MK18 I bought off of Brownells and the bottom SBR is a built upper with a DD MK18 barrel and a Troy MLOK rail that I had from another build. The top lower is a DD that I SBR'd from a M4V5 years ago...so I have a complete/factory DD SBR...just several years of manufacture apart!

I wanted two, almost identical, SBRs so I could use one as my primary HD rifle and the second for when the other was down for some reason. I didn't want to spend the extra $300 or so it would have take to buy a second MK18 upper.

Enough about me. In your position, you could sell the rail off the MK18 for a pretty penny and have more than enough to outfit your pistol with whatever MLOK rail strikes your fancy.

But, personally, I'd keep the DD whole. Either sell it and fund your new upper or learn to love it, just the way it is!